1. //  this applet draws 15 shapes (circles and squares) in random locations
   //  choosing one of 6 colors randomly, and it writes the author's name
   //  in the lower right corner
   
   import java.awt.Graphics;
   import java.awt.Color;
   import java.util.Random;
   import java.awt.FontMetrics;
   
   public class RandDraw extends java.applet.Applet {
       private Random rand;
       private Color[] colors;
       private int width;
       private int height;
   
   //  initialize the array of colors and the random number generator
   //  get the size of the applet
   
       public void init() {
           rand = new Random();
           colors = new Color[6];
           colors[0] = Color.black;
           colors[1] = Color.blue;
           colors[2] = Color.red;
           colors[3] = Color.yellow;
           colors[4] = Color.green;
           colors[5] = Color.magenta;
           width = getSize().width;
           height = getSize().height;
       }
   
       public void paint(Graphics g) {
           int colnum;
           int x,y;
   
   //  each iteration chooses a random number for the color, and a random
   //  position for the shape (on even iterations draw a square, on odd 
   //  iterations draw a circle
   
           for (int i = 0 ; i < 15 ; i++) {
               colnum = (int)(rand.nextDouble() * 6);
               if (colnum == 6)
                   colnum = 5;
               g.setColor(colors[colnum]);
               x = (int) (rand.nextDouble() * (width-15));
               y = (int) (rand.nextDouble() * (height-15));
               if (i % 2 == 0)
                   g.fillRect(x,y,15,15);
               else
                   g.fillOval(x,y,15,15);
           }
   
   //  draw the name in black in the lower right corner
   
           g.setColor(Color.black);
           FontMetrics fm = g.getFontMetrics();
           int messWidth = fm.stringWidth("your name here");
           g.drawString("your name here",width-messWidth-10,height-10);
       }
   }
   

2. //  this applet sets up two TextAreas where the user can type text.
   //  when the user types a character in either TextArea the character
   //  is copied into the other TextArea
   
   import java.awt.*;
   import java.awt.event.*;
   import java.util.Random;
   
   public class NumGuess11 extends java.applet.Applet
                                   implements ActionListener
   {
       private TextField guess;
       private TextField message;
       private Panel guessPanel;
       private Panel msgPanel;
       private Panel buttonPanel;
       private Random rand;
       private int theNum;
       private Button newNum;
       private int width;
       private int height;
   
   //  create two Panels and the two text areas, add the text areas to the 
   //  Panels and add the Panels to the applet the TextAreas are placed 
   //  inside Panels so that their size can be specified
   
       public void init()
       {
           width = getSize().width;
           height = getSize().height;
           rand = new Random();
           theNum = (int) (rand.nextDouble() * 100);
           setLayout( new GridLayout(3,1) );
           guessPanel = new Panel();
           msgPanel = new Panel();
           buttonPanel = new Panel();
           guessPanel.add( guess = new TextField(4) );
           msgPanel.add( message = new TextField(45) );
           buttonPanel.add( newNum = new Button("New Number") );
           add(guessPanel);
           add(msgPanel);
           add(buttonPanel);
           message.setText("Type a number between 0 and 100, then press Enter");
           guess.addActionListener(this);
           newNum.addActionListener(this);
       }
   
   //  this method will receive an event when the user presses the enter key.
   
       public void actionPerformed(ActionEvent e)
       {
           if (e.getActionCommand().equals("New Number"))
           {
               theNum = (int) (rand.nextDouble() * 100);
               guess.setText("");
               message.setText("Type a number between 0 and 100, then press Enter");
           }
           else
           {
               String numstr = guess.getText();
               try {
                   int num = Integer.parseInt(numstr);
                   guess.selectAll();
                   if (num == theNum)
                       message.setText("You guessed it!");
                   else if (num < theNum)
                       message.setText("Try a bigger number...");
                   else
                       message.setText("Try a smaller number...");
                   }
               catch(NumberFormatException ex) {
                   message.setText("Enter a number between 0 and 100");
                   guess.selectAll();
               }
           }
       }
   }
   

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